Synchronous machine starting devices for starting synchronous machines such as generators and motors have been developed. Conventionally, a synchronous machine starting device uses a mechanical distributor which detects the position of a rotor of a synchronous machine, for example, by a proximity switch. However, the mechanical distributor is fragile and is susceptible to noise due to a large amount of wiring.
Japanese Patent Laying-Open No. 2006-271038 (Patent Document 1) discloses an example of a synchronous machine starting device for eliminating the need for such a mechanical distributor. Specifically, this synchronous generator starting device includes an externally communicated converter formed of externally communicated devices such as thyristors and an externally communicated inverter formed of externally communicated devices such as thyristors for converting DC (direct current) power obtained from the converter into AC (alternating current) power, to start a synchronous generator using AC power obtained from the inverter. Then, the synchronous generator starting device includes an AC voltage detector detecting voltage of an armature terminal of the synchronous generator, an AC current detector detecting inverter output current fed from the inverter into an armature of the synchronous generator, an induction voltage operation circuit calculating an in-phase component and a quadrature component with respect to a first reference phase, of induction voltage induced at an armature winding of the synchronous generator by field current of the synchronous generator, from an AC current detection value of the inverter from the output current detector and a first synchronous generator rotational speed estimated value, and a PLL circuit outputting a second reference phase and a second synchronous generator rotational speed estimated value such that the orthogonal component of the first reference phase of the induction voltage from the induction voltage operation circuit is zero. Then, the synchronous generator starting device generates a gate pulse of the inverter at a predetermined control advance angle based on the second reference phase output from the PLL circuit, and, in addition, inputs the second reference phase to the first reference phase of the induction voltage operation circuit and inputs the second synchronous generator rotational speed estimated value to the first synchronous generator rotational speed estimated value of the induction voltage operation circuit.    Patent Document 1: Japanese Patent Laying-Open No. 2006-271038